Managing Volumes

Overview

Containers are not persistent by default; on restart, their contents are
cleared. Volumes are mounted file systems available to pods and their
containers which may be backed by a number of host-local or network attached
storage endpoints.

To ensure that the file system on the volume contains no errors and, if errors
are present, to repair them when possible, OpenShift Container Platform invokes the fsck
utility prior to the mount utility. This occurs when either adding a volume or
updating an existing volume.

The simplest volume type is emptyDir, which is a temporary directory on a
single machine. Administrators may also allow you to request a
persistent volume that is automatically attached
to your pods.

emptyDir volume storage may be restricted by a quota based on the pod’s
FSGroup, if the FSGroup parameter is enabled by your cluster administrator.